CVE-2021-20194 log

Severity Medium
Remote No
Type Privilege escalation
There is a vulnerability in the Linux kernel versions higher than 5.2 and before version 5.11 (if the kernel is compiled with config params CONFIG_BPF_SYSCALL=y , CONFIG_BPF=y , CONFIG_CGROUPS=y , CONFIG_CGROUP_BPF=y , CONFIG_HARDENED_USERCOPY not set, and BPF hook to getsockopt is registered). As result of BPF execution, the local user can trigger a bug in __cgroup_bpf_run_filter_getsockopt() function that can lead to a heap overflow (because of non-hardened usercopy). The impact of the attack could be a denial of service or possibly privilege escalation.
Group Package Affected Fixed Severity Status Ticket
AVG-1561 linux-lts 5.4.96-1 Medium Not affected
AVG-1560 linux-zen 5.10.14.zen1-1 Medium Not affected
AVG-1559 linux-hardened 5.10.14.hardened1-1 Medium Not affected
AVG-1558 linux 5.10.14.arch1-1 Medium Not affected

The issue can be mitigated by setting "sysctl kernel.unprivileged_bpf_disabled=1".